Seedling Selection of Stress Resistance in the 2^nd Superior Families of Castanopsis hystrix

Through the determination of seedling height, ground diameter and resistance physiological indexes of the 2nd generation of 29 Castanopsis hystrix clones, the subordinate function method was used to screen and evaluate the superior family. Results show that there are great differences of all index among the 29 families. The seedling height varies from 36.5 to 74.8 cm, the ground diameter varies from 5.03 to 8.58 mm, the soluble sugar content varies from 3.37% to 5.84%, the starch content varies from 2.01% to 4.09%, the soluble protein content varies from 20.4 to 38.1 mg/g, the proline content varies from 2.66 to 5.04 μg/g, the MDA content varies from 15.6 to 87.5 nmol/g, the POD activity varies from 12.3 to 88.0 μ/(g·min) and the SOD activity varies from 53.2 to 82.9 U/g. All stress resistant indices have significant difference among all C. hystrix families. Using a multi-index comprehensive evaluation method to screen out 10 families as excellent families with stress resistance. At the same time, combined with the height of seedling height and the growth index of ground diameter, the fast-growing resistance of P₃, B₂, A₇ and B₅ families are further selected.